I personally prefer to capture the image as best as I can in the field. For one, I do it right there, it's done and it's done quicker than any post process. Secondly, when I photograph, I photograph in the moment. In other words, I create in the field. The whole process of capturing the image and what I want to accomplish with it is done on the spot, in the moment of its creation. All little tweeks and such can be made later.

Now of course this isn't for everyone. Some folks prefer to dilly around on the computer. I'm not wired that way. I have a hard time seeing and piecing together things later. It's not to say I haven't done the blending stuff and such, it's just that I prefer to do it in the field. Blending of course is a terrific tool for when you are faced with really difficult lighting situations but those situations, for me at least, seem to be far and few. There have only been a handful of cases where my split nd's (for example) haven't been able to solve the issue at hand. Again, I'm put together creatively the way I am and cannot speak for others nor will I refute ones own personal way of expressing their art, regardless of whether I internally agree with it or not.

One digital tool I do employ from time to time however is the Gaussian blur, especially for flowers and various macro work.

you didn't specifically mention circular polarizers, but it's one thing that can't be simulated digitally afaik. i just got one this year, but so far it's pretty much always been on my lens for any outdoor/landscape photos.

My short answer is that post processing is at least as effective, if not more so than using split or graduated neutral density filters. Solid NDs are useful for the soft water effect of extended shutter speeds (the Singh Ray vari-nd will be my next gaget acquisition) and the effect of polarizers on specular highlights can't be duplicated in PS.

In contrast to some of the other posters, I have found using Photoshop to blend exposures much easier than graduated neutral density filters. The time required to mount and carefully alight the filter in the field (generally when perfect morning or evening light is changing by the moment) and the dilemma of an uneven horizon or the inappropriate darkening of a tree/peak that projects into the filtered area are frustrations. Photoshop's HDR tool is still a clumsy work in progress, but it's simple enough to blend two exposures manually with infinitely adjustable results.

I personally find that HDR is the way future is going to be, here is the latest HDR tutorial at naturescapes I have written to the author discussing the HDR, I hope to hear from him , I would post my images here, where I am getting better results with HDR modified work flow.

I come from 4x5 format & fully understand what it means "getting right in the camera" but digital has opened to me a vast choice of that single limited look of the scene when I use filters.

Shooting raw the possibilities are endless & yes it surely is limited to your own processing skills & understanding the theory.

Surely there are few situation where filters are must & HDR wont work (moving elements in scene), infrared & polarization is another area which are not presently available in the digital domain as they alter the physical quality of the light which reach the sensor so cannot be exactly duplicated via PS filters.

The only filters that are always better than PS techniques are IR, polarizers and solid ND (if you want a really slow shutter speed for some reason).

If the DR blend can be done in PS with two versions a single RAW file processed with different exposure settings, then the motion issue is moot, and a ND grad offers no advantages at all. This works well up to about a 2-stop exposure difference. Multi-shot DR blending in PS is only necessary when the DR is extreme (and likely beyond the range of the ND grad anyway) can be done even when there is significant subject motion, as long as the motion doesn't cross the blend transition line. Split ND grad filters are only useful when the transition between the bright and dark areas of the composition follow a straight line, which is a much greater limitation than the subject motion issues encountered when doing blends in PS. A backlit, windblown tree may be difficult to multi-frame DR blend in PS, but a split ND grad will not follow the outline of the tree very well, either. If DR blending in PS won't work, a split ND grad isn't too likely to offer much of an advantage. For these reasons, I don't bother with ND grad filters.

If you are shooting in lighting that has an extremely high or low color temp, a warming or cooling filter can be useful to balance the color channels in the RAW data, so that red pixels aren't getting 2 stops more exposure than blue pixels, or vice versa. But this is a special case, and not of particular concern unless shooting concerts with really bad stage lighting, in a steel mill, or something like that.

With the exception of CP's I really don't use any other filters now. I have several $$$$ worth of split hard/soft edge ND's with variours adapter rings and etc. that are gathering dust. I too, am thinking about the Vari-ND for more field control. Blending and HDR seems to work well for me for wide latitude work..

Last 6 years of digital photography I have not used any filters but wonder at times am I missing something by not using them.

Considering this is asked in the landscape and nature forum, you've been missing a lot IMO if you haven't used a polarizing filter in all that time. I made the choice to start with an ultrazoom digicam when I went digital to avoid having to carry a big camera and a variety of lenses when hiking. This was always such a pain in my film days and there wasn't any other options at that time to have it all in one small package like I can with my current camera. I prefer the convenience and low cost over somewhat lesser final quality compared to a Dslr and big lenses. But I made sure to get one that I could use a polarizer on. The camera I would have preferred from my list of choices did not have this ability and I immediately crossed it off my list. I consider it an essential piece of equipment for photographing many landscape and nature scenes and Photoshop can't duplicate it's effect. (although I have seen examples of it done to a limited extent in some photos) As for the split NDs, they are not cheap and they certainly aren't very convenient to carry around and use and are useful only with a straight horizon. 90% of my chosen scenes that have a dynamic range beyond what the camera can capture don't have the convenience of a straight horizon. I too prefer to capture the image as well as possible in the field. I don't have time to muddle around on the computer trying to fix the mistakes I made out there. I make a note of why a photo turned out poorly, then get rid of it and spend my time tweaking the few good compositions that the camera didn't record as well as I may have liked or may have been recorded well but still might show improvement with a little computer work. To me, the computer is as much a tool as my camera is. Just as ND filters are tools. The choice is simply of which tool to use. My own personal reasoning is simple. If I can blend two images in about 3 minutes on the computer at essentially no cost, I see no reason to invest in costly filters that would have me fiddling in the field for probably the same amount of time per photo and are really only useful for a select few of the high dynamic range scenes I photograph.

While there still seems to be some who stir up controversy about using the computer in the process of creating a finished photo, the computer is a tool just as the camera is a tool and in many cases the camera itself is simply not a good enough tool to record exactly what we want to record no matter how meticulous we are in getting it right in the field. I don't see the computer as way to fix poor photos. I see it as a way to finish good ones. I'll use whatever tools available to that end and if given a choice between accomplishing something on the computer or out in the field, I'll choose the less costly and/or more convenient one.

I'm of the mindset that I still use filters. I guess it's because I started in film, I already own the filters, and I'm comfortable using them. Although I really haven't explored HDR in Photoshop yet, I'm confident that I'd have good results if I was to play around, or at least decent results.

Anyway, I guess what it boils down to for me is that I'm not typically shooting in very high dynamic light situations. Furthermore, I still shoot film quite a bit. For example, I wouldn't feel comfortable taking the following image with a digital camera and expect it to look the same. So using film and filters was a must, IMHO.

Now take a look at the following image for an exception where I didn't use any filters. This was shot with a 1DS-MKII with no filters whatsoever. I was at ISO100, 1/4 second, and f/25, but because of the lighting, I was over-exposed by 2-3 stops. In fact, if you looked at the camera's LCD display, the image was mostly white, and the histogram was far to the right with many clipped pixels. I wanted to stop down more, but couldn't with the camera's settings. (Although I'm aware that I could have selected ISO50, I chose not to for the sake of expediency.) Anyway, to retain the blurred effect, I specifically wanted 1/4 second. This would have most definitely required a solid ND filter to get a proper exposure if I was shooting with film, but because I shot digitally, and RAW at that, over-exposing didn't destroy the shot. Once I got home, I was able to bring the image back into an acceptable range with Camera Raw, and that made the image a keeper. Pretty cool, I think! And I didn't need to worry about filters or anything. Simply grab the shot and move on.